Coleman serial number lookup: age of a furnace, AC or heat pump
The serial number is on the nameplate behind the front panels of a furnace or on the rating plate of the outdoor unit. Coleman serials come in two kinds: York serials that start with letters, and all-digit serials that start with the year and the month.
Decode a Coleman serial number
How to read a Coleman serial number
Coleman has used 4 serial formats. Find the one that matches the shape of your serial.
Letter, digit, letter, digit
The second and fourth characters are digits. Read together they are the year: 0 and 5 make 2005. The letter between them is the month.
Shape: a letter, a digit, a letter and a digit, followed by six digits.
W0K5896070 reads as September 2005.
Month letter
- A January
- B February
- C March
- D April
- E May
- F June
- G July
- H August
- K September
- L October
- M November
- N December
The month letters skip I and J: K is September, L October, M November and N December. One general chart lists J to M for those four months instead. The two York-specific references agree on K to N. Plant letters: A Apodaca, N Norman, S Source One, W Wichita.
All digits: year, then month
The first two digits are the year and the next two are the month.
Shape: nine or ten digits with no letters.
990697368 reads as June 1999.
This all-digit layout is found on Coleman and Coleman-Evcon units built in Wichita. Coleman units from York’s own lines carry York serials with letters.
Four letters: plant, month, year, type
The second letter is the month and the third letter is the year. The first letter is the plant and the fourth is the type of item.
Shape: four letters followed by six digits.
WFKM003094 reads as June 2001.
The same code also fits 1980. Month letter
- A January
- B February
- C March
- D April
- E May
- F June
- G July
- H August
- K September
- L October
- M November
- N December
Year letter
- A 1971, 1992
- B 1972, 1993
- C 1973, 1994
- D 1974, 1995
- E 1975, 1996
- F 1976, 1997
- G 1977, 1998
- H 1978, 1999
- J 1979, 2000
- K 1980, 2001
- L 1981, 2002
- M 1982, 2003
- N 1983, 2004
- P 1984
- R 1985
- S 1986
- T 1987
- V 1988
- W 1989
- X 1990
- Y 1991
The year letters A to N each stand for two years, 21 years apart. The letters P to Y stand for one year each, 1984 to 1991. References disagree on whether this layout began in 1971 or 1980. Some plates print one more letter in brackets in front of the four.
All digits: month, then year
The first two digits are the month and the next two are the year.
Shape: nine or ten digits with no letters.
0188123456 reads as January 1988.
The third and fourth digits are a year between about 70 and 92, so they cannot be mistaken for a month.
Where to find the serial number
On a furnace the nameplate is behind the front access panels. Remove both panels to see it.
On an outdoor unit the rating plate is on the cabinet.
If the serial number does not decode
- Coleman heating and cooling equipment has been built by York’s Unitary Products group since the 1990s. Units from York’s own lines carry York serials with letters. Older Coleman and Coleman-Evcon units built in Wichita carry all-digit serials.
- Choose the layout by the shape of the serial: digits only, or a pattern of letters and digits.
- The manufacturer can confirm the date from the serial: Coleman registration, warranty or serial lookup.
What the age tells you
| Equipment | Typical service life |
|---|---|
| Furnace | 15 to 22 years |
| Central air conditioner | 10 to 21 years |
| Heat pump | 15 to 16 years |
What size is it?
The model number on the same rating plate gives the size: the tonnage of an air conditioner or heat pump, or the heating input of a furnace. York model number tonnage shows where the digits sit and reads them for you.
About Coleman
Coleman entered heating and cooling in 1958. Its equipment business became Evcon Industries in 1990 and was bought by York in the 1990s. Coleman equipment is now built alongside York and Luxaire and moved with them to the Bosch Home Comfort Group in 2025.
Brands that share this serial system: York, Luxaire.
Questions and answers
Which characters in a Coleman serial number show the date?
The second and fourth characters are digits. Read together they are the year: 0 and 5 make 2005. The letter between them is the month. This applies to units built since October 2004.
Why does my Coleman serial number look different?
Coleman has used 4 serial formats: letter, digit, letter, digit (built since October 2004); all digits: year, then month (built since 1992); four letters: plant, month, year, type (built until October 2004); all digits: month, then year (built until early 1992). The decoder tries each one.
The decoder shows more than one possible year. Which one is right?
Part of the Coleman date code repeats, so the serial alone fits more than one year. A manufacture date printed on the rating plate, the print date of the owner’s manual or the installation record settles it. For equipment that is still running, the more recent year is usually the right one.
Who makes Coleman heating and cooling equipment?
Coleman heating and cooling equipment has been built by York’s Unitary Products group since the 1990s. Units from York’s own lines carry York serials with letters. Older Coleman and Coleman-Evcon units built in Wichita carry all-digit serials.
Sources
- York serial numbers identification sheet, “from history to October 2004” (archived dealer copy) (independent reference): https://web.archive.org/web/20171118111839/http://www.usair-eng.com/Serialnumber.pdf
- Building Intelligence Center: York HVAC age (independent reference): https://www.building-center.org/york-hvac-age/
- McGarry and Madsen Inspection: age of a York air conditioner or furnace from the serial number (independent reference): https://www.howtolookatahouse.com/Blog/Entries/2018/6/how-can-i-tell-the-age-of-a-york-air-conditioner-or-furnace-from-the-serial-number.html
- Building Intelligence Center: Coleman HVAC age (independent reference): https://www.building-center.org/coleman-hvac-age/
- McGarry and Madsen Inspection: age of a Coleman or Coleman-Evcon air conditioner or furnace (independent reference): https://www.howtolookatahouse.com/Blog/Entries/2018/10/how-can-i-tell-the-age-of-a-coleman-or-coleman-evcon-air-conditioner-or-furnace-from-the-serial-number.html
- InspectAPedia: furnace age chart (independent reference): https://inspectapedia.com/heat/Furnace_Age.pdf
- CPSC recall: York, Luxaire and Coleman furnaces built May to July 2001, serials starting WFKM or WGKM (US Consumer Product Safety Commission): https://www.cpsc.gov/Recalls/2001/cpsc-york-international-corporation-announce-recall-of-gas-furnaces
- CPSC recall: York Diamond 80 furnaces sold May 1994 to July 1996, serials EECM to EGEM (US Consumer Product Safety Commission): https://cpsc.gov/recalls/2000/cpsc-york-international-corp-announce-recall-of-york-international-corporation-diamond-80-furnaces
Formats last checked against these sources on October 5, 2026. Found a serial that does not fit? Send a correction. How formats are verified: method and sources.